Introduction

Topic Detection and Tracking (TDT) refers to automatic techniques for finding topically related material in streams of data such as newswire and broadcast news. The TDT3 corpus was created to support three TDT3 tasks: find topically homogeneous sections (segmentation), detect the occurrence of new events (detection), and track the reoccurrence of old or new events (tracking).

The goal of Topic Detection and Tracking - Phase 3 (TDT3) is to create core technology to monitor multiple streams of news in multiple languages and media (newswire, radio, television, web sites or some future combination or innovation), segmenting the streams into individual stories, detecting new topics and tracking all stories discussing them. In additional to the TDT2 tasks of segmentation, detection and tracking, TDT3 adds the tasks of first story detection and story-link detection. The goal of the latter is to detect links between stories that discuss the same topic even though the topic has not been defined in advance.

Data

The TDT3 English Audio Corpus contains the audio (in compressed sphere format) of news broadcasts collected daily from six news sources in American English, over a three-month collection period (October - December 1998). The sources and amounts are as follows:

The files in this publication are complete single-channel recordings of the (30 or 60-minute) broadcasts listed above. Each one has been digitized at a sample rate of 16 KHz using 16-bit samples, and compressed using the "shorten" algorithm.

(The audio CD-ROMs are grouped into subsets by broadcast source and the LDC will support the option of purchasing one or more subsets, e.g. just the ABC data. We regret that we cannot provide "customized" subsets.)